Magnetic retrievers



Feb, 16, 1965 G TWACHTMAN I MAGNETIC RETRIEVERS Filed Jan. 18. 1962Press EFM s fawn? mam 6 t Inventor:

Godfrey Tvmchtmon tied and the cost of production materially reduced.

United rates Patent filice 3,169,791 Patented Feb. 16, 1965 MAGNETICRETRIEVERS Godfrey 'Iwaehtrnan, 618 N, Deiaware, Independence, Mo.

Filed Jan, 18, 1962, Ser. No. 167,1]ld ll tClairn, (Cl. 294-=-t5.5)

This invention relates to new and useful improvements in magneticretrievers for use in picking up objects of magnetically attractablemetal from poorly ac cessible locations, and in particular the inventionrelates to certain improvements in the retriever disclosed in UnitedStates Patent No. 2,993,723, issued July 25, 1961, jointly to GodfreyTwachtman and John A Ware.

When placing the retriever in accordance with the aforementioned patentin production I found that the same lends itself to certain structuralmodifications, particularly from the standpoint of assembly of themagnet and shaft, whereby manufacture is considerably simpli- It is,therefore, the principal object of the present invention to provide amagnetic retriever wherein such improvements, are embodied.

Other objects, features and advantages of the present invention willbecome apparent from the following description taken in conjunction withthe accompanying drawing, wherein like characters of reference are usedto designate like parts, and wherein:

FIGURE 1 is an elevational view of a magnetic retriever in accordancewith the present invention;

FIGURE 2 is an enlarged, fragmentary longitudinal sectional view takensubstantially in the plane of the line 22 in FIGURE 1;

FIGURE 3 is a cross-sectional view, taken substantially in the plane ofthe line 33 in FIGURE 2; and

FIGURE 4 is a cross-sectional view, taken substantially in the plane ofthe line 4- t in FIGURE 2.

Referring now to the accompanying drawing in detail, the magneticretriever in accordance with the present invention is designatedgenerally by the reference numeral and embodies in its constructionaresiliently flexible, slender shaft 11 which is normally straight butmay be bent to any desired form during use of the tool. The shaft 11consists of a core in the form of a closely wound helical spring 12which is'completely covered by a tubular jacket 13 of synthetic plasticmaterial, whereby to protect the spring against dirt, moisture, and thelike.

One end portion of the spring 12 projects outwardly from the jacket 13and is press-fitted into one end portion of a tubular sleeve or casing14, which is preferably although not necessarily made of brass or someother non-magnetizable material. The adjacent endportion of the jacket13 is stretched and tightly fitted over the sleeve or casing 14, asindicated at 15 so as to prevent access of moisture, et cetera, to theinterior of the sleeve and spring therein.

A cylindrical permanent magnet 16 is press-fitted into the other endportion of the sleeve 14 and is permitted to project outwardly therefromto some extent as shown, the inner end of the magnet preferably beingspaced from the adjacent end of the spring 112; to provide an air gap17.

It will be apparent from the foregoing that the present inventionutilizes a simple tubular sleeve 14 for connection of the magnet 16 tothe spring 12 of the shaft ill, so that the use of aspecially'machinedhousing such as exists in the aforementioned patent is not required.Moreover, the spring and the magnet are of the same diameter so thatthey may both be press-fitted into the simple tubular jacket without theuse of a keeper pin to hold the magnet in place. Also, the pole piece ofthe aforementioned patent is eliminated, thus leaving the portion of themagnet which projects from the sleeve to come in direct contact with thework.

The free end of the shaft 11 is provided with an I- shaped finger piece118 which may either be separately formed and secured to the spring 12,or be constituted by forming the last few convolutions of the springinto the finger piece, as desired.

While in the foregoing there has been described and shown the preferredembodiment of the invention, various modifications may become apparentto those skilled in the art to which the invention relates. Accordingly,it is not desired to limit the invention to this disclosure and variousmodifications and equivalents may be resorted to, falling within thespirit and scope of the invention as claimed.

What is claimed as new is:

In a magnetic retriever, the combination of a straight tubular sleeve ofnon-magnetizable metallic material having a bore of a constant diameteropen at both ends thereof, a tightly wound helical spring having one endportion thereof press-fitted into and tightly held in one end portion ofthe bore of said sleeve, a cylindrical permanent magnet of the samediameter as said spring pressfitted into and firmly held in the otherend portion of the bore of said sleeve and projecting outwardlytherefrom, the inner end of said magnet in said sleeve being spacedlongitudinally from the adjacent end of said spring to provide an airgap therebetween, and a tubular. plastic jacket enclosing said spring,an end portion of said jacket being radially stretched and tightlyfitted over said sleeve.

References Cited in the file of this'patent UNITED STATES PATENTS

